Pretty sure refusing to work when given the option is itself not considered "good behavior." It's one of the ways they coerce inmates into working those $0.12/h jobs.
You can get a shot for refusing to work. This can impact good time and will impact your points. Higher points mean you get sent to a higher security (which ironically means less secure/safe for the inmate) facility.
[1]: https://www.tdcj.texas.gov/faq/cid.html#work